HVAC safety shutoff system

ABSTRACT

An emergency system is disclosed for venting smoke-filled air outside of a building during a fire in which the air conditioning and/or heating system forms part of the emergency system.

RELATED APPLICATION

[0001] This Application relates to Provisional Application Ser. No. 60/200,901, filed May 1, 2000 which is hereby incorporated by reference.

BACKGROUND

[0002] Each year many lives are lost in fires in homes and commercial structures, not from contact with the fire or from the heat, but due to inhalation of the smoke. Even when a person is several or many rooms away from the room where the fire starts, the smoke-filled air from the room with the initial fire flows to the other rooms through the individual ducts forming the ventilation system. Thus, the blower in the air conditioning unit actually draws smoke-filled air into the unit and circulates it through the ventilation ducts to all of the other rooms of the building.

SUMMARY

[0003] The present invention provides an emergency system for discharging smoke-filled air to atmosphere outside of a building in which the blower of the air conditioning and/or heating system is used to discharge the smoke-filled air.

BRIEF DESCRIPTION OF DRAWINGS

[0004]FIG. 1 is a schematic side view in cross-section of a conventional air conditioning unit with the emergency system of the present invention; and

[0005]FIG. 2 is a schematic, fragmentary side view in cross-section of a second embodiment of the emergency system.

DETAILED DESCRIPTION

[0006] As shown schematically in FIG. 1, a conventional central air conditioning unit or “air handler” 10 includes a housing 12 which encloses an evaporator 14 through which the air is pulled upwardly by a blower 16 driven by a motor 18. The return air from the home or commercial structure, hereinafter the building, enters unit 10 through a return duct 20 as shown by arrow A. The air flows upwardly through the refrigeration unit 14, and normally flows directly into the ventilation duct system 25 which supplies the cooled air to the individual rooms of the building.

[0007] Such a conventional air conditioning system performs well for the intended purpose of cooling a building. However, if there is a fire, smoke-filled air is drawn in through return duct 20, and the smoke-filled air is circulated to all of the rooms through the individual ventilation ducts to each room. This multiples the killing effect of the smoke by circulating the smoke from the first room where the fire starts to all of the other rooms. In addition, if the fire progresses to another room, the conventional air conditioning system continues to circulate even more smoke to all of the other rooms.

[0008] In the present invention, the smoke is not circulated to other rooms, but rather, the smoke is immediately vented outside of the building. This is accomplished by the provision of an emergency smoke shut off unit 30 which is positioned above the conventional air handler 10. Smoke shut off unit 30 includes a housing 31 having an upper discharge opening 32 which connects to the ventilation system 25. In addition to opening 32, through which the refrigerated air flows during normal operation as shown by arrow B, shut off unit 30 includes an emergency vent opening 34 connected to an emergency vent duct 36 which extends to a position in communication with the atmosphere outside of the building. The flow of air through normal discharge opening 32 is controlled by, for example, a set of louvers 32 or other flow control devices such as dampers or the like. Similarly, the flow through vent opening 34 is controlled by, for example, a set of louvers 40 or other flow control devices such as dampers on the like. Louvers 38 are actuated from their normally open position to their closed position by a motor or solenoid 42, and louvers 40 are moved from their normally closed position to their open, vent position by a motor or solenoid 44.

[0009] The emergency shut off system further includes a smoke detector 46 which may be physically positioned within housing 12 as shown, or within return duct 20, or elsewhere in the path of the smoke. Detector 46 is operatively connected to a pair of override switches 48A, 48B which actuate motors or solenoids 42 and 44.

[0010] The present invention operates as follows. During normal conditions, louvers 38 are in their open position such that refrigerated air shown by dotted arrow B is discharged from air handler 10 into the ventilation system of the building to cool the multiple rooms of the building. In this normal mode, louvers 40 are closed. However, whenever smoke is sensed by detector 46, override switches 48A and 48B reverse the positions of louvers 38 and 40 so that the discharge of smoke-filled air is prevented from being recirculated through the ventilation system to the multiple rooms of the building. Instead, the smoke-filled air is discharged to atmosphere outside of the building through vent duct 36 thereby removing the smoke instead of spreading it to all of the other rooms.

[0011] From the foregoing description of one preferred embodiment of the invention it will be apparent to those skilled in the art of heating/cooling that the invention is not limited to air conditioning units, but rather, unit 10 may be a furnace, or a combination of furnace and air conditioning unit. Also, it will be apparent that the form of flow control valves may be of various structural forms. For example as shown in FIG. 2, they may comprise simple dampers 38′ and 40′ which may be opened and closed by actuators 42′ and 44′. It will also be apparent that the louvers or dampers in the vent duct may be biased to their closed position by weights or springs so as to be opened by air pressure when louvers 38 or damper 38′ is closed. In this manner, motor or solenoid 44, 44′ may be eliminated, and it will be understood that switches 48A, 48B may comprise solid state elements in a solid state control system. It will also be noted that while the emergency shut off system may be manufactured to mount upon existing A.C. and heating systems as shown in FIG. 1, new A.C./Heating systems may include the shut off system as an integral unit as shown in FIG. 2

[0012] These and many other variations and modifications of the invention will become apparent to those skilled in the art. Accordingly it is to be understood that the foregoing description of the principles of the invention is intended to be illustrative and not exhaustive of the invention, and that the invention is not intended to be limited other than as expressly set forth in the following claims. 

What is claimed is:
 1. An emergency system for discharging smoke-filled air from a building through an air conditioner and/or furnace unit including a conventional return duct, a conventional discharge duct and a blower comprising: (a) a smoke detector positioned in the path of the smoke-filled air through the unit; (b) a first flow control valve in said conventional discharge duct; (c) a vent duct having one end connected to said unit and the opposite end communicating with the atmosphere outside of the building; (d) a second flow control valve in said vent duct; and (e) electrical control means actuated by said smoke detector and connected to each of said flow control valves for closing said first flow control valve and opening said second flow control valve for preventing circulation of the smoke-filled air in the building and venting the smoke-filled air to atmosphere outside of the building.
 2. The emergency system of claim 1 wherein at least one of said first and second flow control valves comprises a damper.
 3. The emergency system of claim 1 wherein at least one of said first and second flow control valves comprises a plurality of louvers.
 4. The emergency system of claim 1 wherein at least one of said first and second flow control valves is controlled by a motor.
 5. The emergency system of claim 1 wherein at least one of said first and second flow control valves is controlled by a solenoid.
 6. The emergency system of claim 1 wherein said electrical control means include override switches for actuating said first and second flow control valves.
 7. The emergency system of claim 1 wherein said electrical control means include solid state circuit means for actuating said first and second flow control valves.
 8. The emergency system of claim 1 wherein said unit is a central air conditioner unit.
 9. The emergency system of claim 1 wherein said unit is central heating unit.
 10. The emergency system of claim wherein said unit is a combined central air conditioning and heating unit.
 11. The emergency system of claim 1 wherein one of said first and second flow control valves comprises a damper biased to the closed position.
 12. An emergency smoke shut off system for use with an air handler having a blower and a normal discharge opening comprising: (a) a housing of a size and shape to be mounted above the air handler; (b) said housing including a first discharge opening for flowing air during normal operation; and (c) said housing including a second vent opening for venting smoke-filled air during a fire.
 13. The shut off system of claim 12 wherein said first discharge opening extends horizontally and said second vent opening extends vertically.
 14. The shut off system of claim 12 including first flow control means for opening and closing said first discharge opening.
 15. The shut off system of claim 12 including second flow control means for opening and closing said second vent opening.
 16. The shut off system of claim 14 including a smoke detector, and actuator means connected to said smoke detector for closing said first flow control means when smoke is detected by said smoke detector.
 17. The shut off system of claim 15 including a smoke detector, and actuator means connected to said smoke detector for opening said second flow control means when smoke is detected by said smoke detector.
 18. The shut off system of claim 16 wherein said first flow control means comprise a plurality of louvers. 